EP 0 757 749 B1 relates to gas turbine engines. A pair of root rails is provided on the bottom of a dovetail-shaped root portion of a gas turbine engine blade to minimize reciprocating tangential motion of the blades within the dovetail shaped slots in which the root portions of the blades are retained. Each root rail is wedge shaped, tapering in a decreasing cross section from the base of the root toward the aerofoil platform.
In view of the above-described situation, there exists a need for an improved technique that enables to provide for an efficient assembly of a turbomachine.